Grate-bar



(No Model.)

L. HALL 81; O. J. EARTH.

GRA-TE BAR.

v1 I0.410,669. Patented Sept.10,'1889.

UV VE/VTURS wgw WITNESSES. M fa UNITED STATES PATENT .OFEIcE.

LESTER HALL AND OTTO JOSEPH EARTH, OF KANSAS CITY, MISSOURI.

GRATE-BAR.

SPECIFICATION forming part of Letters Patent No. 410,669, dated September 10, 1889.

Application filed January 7, 1889.

To all whom it may concern.-

Be it known that we, LESTER HALL and OTTO J OSEPH BARTH, both citizens of the United States, residing at Kansas City, in the county of Jackson and State of Missouri, have invented certain new and useful Improvements in Grate-Bars for Furnaces; and we do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

Our invention belongs to that class of gratebars which has as an ultimate object not only to supply the fuel with a freer circulation of air than has been heretofore achieved, but also to so construct the bars that the airspaces will not only not choke up or become clogged by usage, but that the same will also gradually enlarge in course of timethat is, as the upper surface of the bars nearest to the fire will gradually wear and burn away and yet leave an abundance of f uel-surface in the grate. The construction of our bars is also such that the same are less liable to warp and spring, from the fact that they do not need to be placed close together in order to give the proper amount of bearing-surface for the fuel, but they are each provided with an air-space running longitudinally the entire length of the bar where exposed to the fire.

Our invention consists of a central web having upward projections of angular shape diverging in opposite directions. By this arrangement the greater bulk of the metal of the bar which rests in the web is entirely removed from the direct action of the fire. This enables us to make, in practice, the air-space slightly wider than the thickness of the angular projections, which latter form the fuelsurface, and thereby increasing the amount of air-space considerably and reducing the number and cost of the bars.

In the accompanying drawings, Figure 1 is a plan view of a number of graiebars placed in position. Fig. 2 is a perspective view of a part of our grate-bar, shown in an enlarged scale. Figs. 3 and 4 are cross-sectional and side views of the same.

Serial No. 295,700. (No model.)

In thedrawings, A is the central bar or web, which is beveled at its top at a, so as to prevent ashes and cinders from lodging upon the same and thereby blocking up the air-spaces. The central web A supports a number of upward angular projections B. The top I) of the latter forms the fuel-surface proper, and is considerably elevated above the beveled top a of the web A, thereby removing the latter entirely from the fire-surface and producing a series of uninterrupted air-spaces throughout the entire width of the grate.

\Ve are aware that grate-bars have heretofore been made with angular projections; but the same have formed a part of the supporting-web, and have not allowed the air to circulate freely and above thelatter, as is the case in our invention.

The top Z) of our gratebar is plain, as in practice the action of the fire will rapidly burn away any ridges or sharp edges caused by corrugations in the upper surface, while at the same time a scraper or stoker-bar will more easily pass over the plain surface. The front and rear edges of each bar are slightly rounded, as at O C, for the easy admission of the fire-tools.

As seen at D in Figs. 2 and 4, the sides of the projections or fingers B are beveled downwardly for a certain distance, and are then carried perpendicularly onward to their intersection with the web A. We hereby effeet the necessary clearance between two adjoining fingers B more rapidly than by gradually beveling the same, and at the same time insure a gradually-enlarging air-space proportionate to the wearing and burning away of the upper fuel-surface.

In order to produce an air-space between two adjoining bars, we have enlarged laterally the two end projections O and O, and also the central projection B of each bar. When placed in position, these three projections 15, C, and C will meet, while the ends of the intermediate projections 13 will leave an area for air-circulation between themselves. This prevents the liability of warping, increases the amount of air-supply, and reduces the number and weight of bars.

The main and distinctive feature of ourinvention consists in the sharp and abrupt clearance between each pair of adjoining fin gers or projections, as illustrated at D in the drawings. This produces, together with the V-shaped form of the fingers, a shearing propensity as soon as the sliding bar is pushed across the fire-surface. It has been found impossible heretofore to remove effectively all particles of clinkers and ashes from between the air-spaces of the grate. The residue tended to slowly accumulate and thereby to injure the draft, while by means of our invention the angularly-shaped projections, with their sharp upper edge and short clearance between each two adjoining fingers, are operated upon by the sliding bar in the hands of the fireman and produce reciprocally a shearing action toward the dislodgment of all obstructions within the air-spaces of our bars.

NVe are aware that several forms of gratebars have been constructed with'a series of flanges, the latter forming, in someinstances, an are above the bar'for the purpose of supporting the coal in arches. Such an arrangethe latter being of angular shape, diverging outwardly in opposite directions, and so arranged that the Web or central portion of the bar will be entirely below the fuel-surface and admit of a clear air-circulating space between the fire-surface proper and the top of the web, as herein described.

2. In a grate-bar, a central Web with up- .ward angular projections so arranged that LESTER HALL. OTTO JOSEPH EARTH.

Witnesses:

S. W. SPANGLER, ERNEST ABSHAGER. 

